Twinned Watersheds Project:
In 2021, the Twinned Watershed Project studied how the riparian zones, the terrestrial part of riparian ecosystems, are impacting fish habitat. Riparian field crews assessed sites along lower reaches of the Koksilah and Chemainus Rivers to see how well the trees and shrubs are doing at preventing streambank erosion and filtering surface water, as well as providing fish refuge when they fall in the river. They also assessed culturally significant plants such as western redcedar, a keystone species in Indigenous culture. Land use along the rivers was mapped and several priority sites were identified for invasive plant removal and planting native species. Riparian restoration work was also done at three local farms.
Riparian plant crew looked for big trees that provide benefits as in-stream structures for fish habitats and on the forest floor to slow the flow of water. Photo by Heather Pritchard
The Twinned Watersheds Project of the Chemainus River and Koksilah River in the Cowichan Region of southern Vancouver Island assessed salmonid habitat, water flow regimes, and riparian habitat within the lower reaches of the main rivers. The fish habitat information is presented in a separate report. This part of the Twinned Watersheds Project focused on…
A 50-metre deep riparian zone was studied along some stream reaches to learn how the health of the forests is affecting the health of fish habitat.